Method for developing silver halide photosensitive material

ABSTRACT

A PHOTOGRAPHIC DEVELOPING PROCESS WHICH COMPRISES: DEVELOPING AN EXPOSED LIGHT SENSITTIVE SILVER HALIDE EMULSION LAYER OF A PHOTOGRAPHIC MATERIAL WITH AN ALKALINE SOLUTION IN THE PRESENCE OF HYDROQUINONE AND A DERIVATIVE OF P-AMINOPHENOL HAVING THE FORMULA:   2,6-DI(H3C-),4-(R-N(-(CH2)N-OH)-)-PHENOL   WHEREIN R IS AN ALKYL GROUP OF FROM 1 TO 4 CARBON ATOMS, AND N IS AN INTEGER OF FROM 2 TO 5.

July 2, 1974 su ARA] ETAL 3,822,130

METHOD FOR DEVELOPING SILVER HALIDE PHOTOSENSITIVE MATERIAL Filed Oct.27. 1971 DENSITY (D) DEVELOPMENT TIME (SECS) Patented July 2, 1974 3 822130 METHOD FOR DEVIZLOIING SILVER HALIDE PHOTOSENSITIVE MATERIAL AtsuakiArai, Kinji Ohkubo, Tasuya Tajima, Mitsugu ABSTRACT OF THE DISCLOSURE Aphotographic developing process which comprises: developing an exposedlight sensitive silver halide emulsion layer of a photographic materialwith an alkaline solution in the presence of hydroquinone and aderivative of p-aminophenol having the formula:

OH R a wherein R is an alkyl group of from 1 to 4 carbon atoms, and n isan integer of from 2 to 5.

BACKGROUND OF THE INVENTION (1) Field of the Invention The presentinvention relates to a method for developing a silver halidephotosensitive material. More particularly, it has as its object theimprovement of the developing activity of hydroquinone by the use ofhydroquinone in combination with a specific compound as a developingagent.

(2) Description of the Prior Art Photosensitive materials haveheretofore been prepared by coating a photosensitive silver halideemulsion on a support base, such as glass plate, paper, plastic filmetc., followed by drying the coated product. After the thus preparedphotosensitive material has been exposed to light, it is developed witha developer liquid, which is an alkaline aqueous solution containing adeveloping agent as its essential ingredient, thereafter it is subjectedto the steps of stopping, fixation and various water-rinsing treatmentsin sequence.

Since these series of treatment procedures, however, require a longperiod of time, many improvements to date have been proposed in the artin order to shorten the processing time. Examples of such improvedmethods include high temperature processing, single bath developing andfixation, a double bath type stabilization treatment process, etc. Oneof the most currently employed methods for shortening the time ofdevelopment comprises adding a developing agent to a silver halideemulsion layer, then treating the layer with a highly alkaline aqueoussolution containing an alkali agent and other photographic additives,such as an antioxidant and a retarder. The advantageous feature of thatmethod resides in making a quick development process possible within ashortened developing reaction time, which is brought forth by the use ofa highly increased pH processing liquid. This is only possible when nodeveloping agent is added to the processing liquid employed withoutcausing any degradation on the storability of the liquid.

The silver halide photosensitive material to be suitably employed inthat method includes a silver chloride emulsion and a silverchlorobromide emulsion having less silver bromide content, whichoriginally has a high rate of developing reaction.

On the other hand, various attempts have been made so as to apply asimilar quick process, even to a silver chlorobromide emulsion of highersilver bromide content, pure silver bromide emulsion and silveriodobromide emulsion, by adding a developing agent to these emulsions.However, since each of these silver chlorobromide solutions, pure silverbromide emulsions and silver iodobromide emulsions have a slowerdeveloping reaction rate than that of the silver chloride emulsion, ithas been impossible to obtain satisfactory desirable photographcharacteristics by treatment within a short period of time.

Meanwhile, it is well known in the art that excellent photographiccharacteristics, which have never been attained with the use ofhydroquinone alone, can be obtained in the usual development process forsilver halide photosensitive emulsion containing no added developer, byusing a developing liquid containing hydroquinone in combination with adeveloping agent having super additivity, such as1-phenyl-3-pyrazolidone and N-methyl-p-aminophenol (PQ or MQ developer).In addition, it is disclosed in the specification of US. Pat. No.2,751,297 that the rate of the developing reaction is accelerated by theaddition of 1-phenyl-3-pyrazolidone to a single hydroquinone solution orto MQ developer.

By utilizing these prior teachings, we have made an attempt so as toaccelerate the quick development using a silver chlorobromide emulsion,silver bromide emulsion and silver iodobromide emulsion, each containinga developing agent admixed therein. It was found, however, that theaddition of these accelerators, i.e., 1-phenyl-3- pyrazolidone,N-methyl-p-aminophenol, etc. to these emulsions was unsuccessful,because these accelerator compounds are very susceptible to undergooxidation, which in turn not only causes degradation in the activity ofthese compounds during storage of the resulting articles, but alsoresults in discoloration or contamination of the support base.

It has also been reported that certain p-arnino-phenol derivatives, suchas compound (I), which is disclosed in Japanese Patent Publication No.Sho. 37/5,993, and compound (II), which is disclosed in Us. Pat. No.3,265,499, have more excellent super additive power than theabovementioned 1 phenyl 3 pyrazolidone and N-methyl-paminophenol whenthey are used in combination with hydroquinone.

We have also made an attempt so as to improve the above drawbacksencountered in the use of the compound set forth in the aforementionedUS. patent, by adding such compounds to the emulsion. However, thisprocedure also gave unsuccessful results in that the photosensitiveemulsion containing such compounds caused a fog, and a countermeasurefor the prevention of fogging by resorting to the addition of a knownfog inhibitor caused an appreciable drop in the developing speed.Compounds (I) and (II) of Japanese Patent Publication No. Sho. 37/5 ,993and US. Pat. 3,265,499, discussed above, are as follows:

wherein each of X and X is, for example, a hydrogen atom, a halogenatom, an alkyl group, an alkyl ammo group, etc., respectively.

SUMMARY OF THE INVENTION We have now found that the aforementioneddisadvantages can now be overcome by the addition to a silver halidephotographic emulsion of a compound represented by the formula (III) incombination with hydroquinone, and also that excellent photographiccharacteristics can be obtained by developing this photographic materialwith a single hydroquinone developer. We have also discovered that analkaline developer liquid containing the compound represented by formula(III) together with hydroquinone is an excellent photographic developerliquid.

E; (III) wherein R is an alkyl group containing 1 to 4 carbon atoms andn is an integer of 2 to 5.

The primary object of the present invention is to improve thephotographic characteristics in a conventional rapid developing processof photographic paper, by adding the above-mentioned compound of formula(III) into the silver halide emulsion layer and/or adjacent layer, suchas protective layer or undercoat layer containing a developing agentadmixed thereto.

The second object of this invention is to employ a compound of theformula (III) as an essential developing agent having super additivitywhen being combined with hydroquinone for developing monochromic andcolor photography.

The third object of this invention is to accelerate the developing speedof the usual developing treatment by adding the compound of formula(III) into either one of the emulsion layer, protective layer andundercoat layer of a silver halide photosensitive material containing node' veloping agent added thereto.

DETAILED DESCRIPTION OF THE INVENTION The novel developing agent of theabove formula (III) may be usually used in the form of stable salts suchas hydrochloride or sulfate rather than in the form of the free amine.More particularly, the compound of formula (III) identified hereinafterhave proved to be very suitable for being applied in the processaccording to the present invention:

none in the process, material and/or alkaline solution of the presentinvention as follows:

Amount per mole of light sensitive Proportion per er 0 etween Compoundto be added Toalkaline solution by weight Hydroquinone Layer 5 to 500grams 1 Compound (III) .-d0.-. 0.05 to 50 grams... l/100-1/10Hydroquinone do 5 to 500 grams Compound (III) Solution 0.01 o 20 gramsHydroquinone d 1 to 70 rams Compound (111).. 0.05 to 50 gramsHydroqumone 1 to 70 grams 1 Compound (III) do 0.01 to 20 grams.--1/100-l/l0 The effect of the addition of the compound of the generalformula (III) is displayed against every one of pure silver chloride,silver chlorobromide, pure silver bromide and silver iodobromide, but anoutstanding elfect is obtained when it is used in combination with asilver chlorobromide, a pure silver bromide or a silver iodobromideemulsion, each of which is known to have a slower developing speed.

The development agent to be used in combination with the compounds offormula (III) in accordance with the present invention is not limited toany specific type, and it is possible to use any compound, which isconventionally used as a photographic developing agent having a reducingactivity. Such developing agents typically include hydroquinone or itsderivatives, catechol or its derivatives, ascorbic acid and likecompounds.

The support material to be used for carrying the silver halidephotosensitive material may be any one of those capable of providing asilver halide emulsion with it, and typically exemplified by paper,glass, and plastic film, which may be further provided with a barytalayer or undercoat layer.

The silver halide emulsion to be used is intended to include a silverhalide photosensitive material, and may contain gelatin or anothersynthetic resin such as polyvinyl alcohol, polyvinyl acetal and thelike.

Since the compounds of formula (III) are novel, the method for preparingthe same will be explained in detail below.

SYNTHETIC EXAMPLE 1 4- (N-ethyl-N-B-hydroxyethylamino)-2,6-

dimethylphenol hydrochloride A 500 ml. autoclave was charged with 39 g.of 2,6-di methylhydroquinone and 217 g. of a 40% aqueous ethylaminesolution, then heated, after replacing the entrapped air with nitrogen,at 200 C. for 24 hours with stirring. After being allowed to cool, thereaction product mixture was poured together with 400 g. of ice into 180ml. of concentrated hydrochloric acid to thereby gradually form theprecipitation of white crystals. These crystals were collected andtreated with decoloring charcoal followed by recrystallization fromdilute hydrochloric acid to give 4-ethylamino-2,G-dimethylphenolhydrochloride.

A mixture comprising 10 g. of the thus prepared4-ethylamino-2,6-dimethylphenol hydrochloride, 6.5 g. ethylenebromohydrin, 7.1 g. of anhydrous potassium carbonate and ml. of ethanolwas heated under reflux for 8 hours in a nitrogen atmosphere. Aftercooling the reaction product mixture in a nitrogen atmosphere, it wasfiltered under suction and the residual solid mass on the filter paperwas washed twice with ethanol. The filtrate and wash liquid werecombined together, and the mixture was distilled under reduced pressureto distill off ethanol to leave a residue, which was impregnated twicewith hot ether. After removing the ether by distillation, it was furtherdistilled under a reduced pressure of l mm./Hg. The distilled productobtained after raising the oil bath temperature to 250 C. was thendissolved in ether and dry hydrogen gas was introduced to the resultingsolution to give an oily product, which soon solidified.Recrystallization of the solid product so obtained from ethanol-benzenegave the desired product.

SYNTHETIC EXAMPLE 24-(N-methyl-N-fi-hydroxyethylamino)-2,6-dimethylphenol hydrochlorideThis compound was prepared according to a manner similar to that ofExample 1, from 10 g. of 4-methylamino-2,6-dimethylphenol hydrochloride,which per se was obtained by using 40 g. of 2,6-dimethyl hydroquinoneand 200 g. of 40% aqueous methylamine, 6.95 g. of ethylene bromohydrin,7.6 g. anhydrous potassium carbonate and 100 ml. of ethanol.

The present invention will be more adequately defined by reference tothe following examples, which are merely intended to be illustrative andnot limitative of the present invention.

EXAMPLE 1 Coating solutions were each prepared by adding a requisitehardening agent, a coating adjuvant and each developing agent as shownin Table 1, which follows, to 400 cc. of a silver halide gelatinemulsion containing 50 g. of gelatin and g. of silver chlorobromidehaving a silver bromide content of 60 mol percent.

Each coating solution thus prepared was applied to a photographic barytapaper of 150 g./m. The coated paper was further provided, under a setstate before drying of the coated emulsion layer, with a protectivecoating layer consisting of 20 g. of gelatin, 6 cc. of saponin (as a 6%solution in methanol) and one liter of water, and thereafter dried togive each sample of A-G. The photographic paper thus prepared wasexposed to light through an optical wedge (step wedge) and developedwith the use of an activated solution having a composition as follows:

Composition of activated solution: G. Anhydrous sodium sulfite 45Potassium hydroxide 48 Potassium bromide 1.3

Water to make the entire solution to 1000 cc.

After stabilizing this with a stabilizer solution containing ammoniumthiocyanate (NH SCN), the photographic characteristics were measured andthe results are given in Table 1 as follows:

TABLE 1 Photographic characteristics Specific SellSb tivity SampleComposition of developing agents Maximum density Gamma From Table 1, itwill be noted that Sample G to which the compound of this invention wasadded exhibits a remarkably high value in every sensitivity, maximumdensity and gamma, and has excellent quality.

EXAMPLE 2 A coating solution was prepared by adding a necessaryhardening agent and a coating additive to 400 cc. of a silver halidegelatin emulsion containing 50 g. of gelatin and 20 g. of silveriodobromide in which the silver iodide content was 1.5 mol percent. Thiscoating solution was applied to a photographic baryta paper of 150 g./m.The thus coated paper was further provided under a set state beforedrying of the coated emulsion layer, with a coating solution comprising20 g. of gelatin, a mixture of g. of hydroquinone with 1.5 g. of4-(N-methyl-N-l8- hydroxyethylamino)-2,6-dimethylphenol hydrochloride asan essential developing ingredient, 2 g. of sodium benzene sulfinate asan antioxidant for the developing agent, 3 cc. of a 30% aqueous formalinsolution, 6 cc. of a 6% meth- 6 anol solution of saponin and one literof water, and thereafter dried.

A comparative sample was similarly prepared, but adding no4-(methyl-N-[B-hydroxyethylamino)-2,6-dimethylphenol.

The thus prepared samples were each treated according to a mannersimilar to Example 1. The sample of this invention exhibited superiorvalues in every sensitivity, maximum density and in gamma to the controlsample.

EXAMPLE 3 A photographic baryta paper of g./m. was coated with asolution comprising 50 g. of gelatin, 35 g. of hydroquinone, 1.7 g. of4-(N-ethyl-N-B-hydroxyethylamino)-2,6-dimethylphenol xylenolhydrochloride, 2 g. of sodium benzene sulfinate as an antioxidant forthe hydroquinone, 2 cc. of a 30% aqueous formalin solution, 1.0 g. of afluorescent whitening agent Blankophor BUP (trade name, manufactured byBayer Co., West Germany) and one liter of water. Onto this there wascoated a coating solution comprising 400 cc. of a silver halide gelatinemulsion containing 20 g. of silver chlorobromide in which the contentof silver bromide was 60 mol percent, and other necessary additives,such as a hardening agent and a coating adjuvant. The thus coated paperwas further provided, under a set state before drying of the coatedemulsion, with a protective layer by coating thereon, a solutioncomprising 20 g. of gelatin, 6 cc. of a 6% methanol solution of saponinand one liter of water.

On the other hand, a contrast sample was similarly prepared, but addingno 4 (N-ethyl-N-fi-hydroxyethylamino)-2,6-dimethyl phenol hydrochloride.

Both samples (photographic paper) thus prepared were subjected to asimilar treatment to those described in Example 1. It was noted that thesample according to this invention, i.e., 4(N-ethyl-N-p-hydroxyethylamino)-2,6- dimethylphenol was added to theundercoat layer thereof exhibited excellent photographic characteristicswith extremely higher values in sensitivity, maximum density and ingamma than those obtained with the control sample.

EXAMPLE 4 A coating solution was prepared by adding a necessaryhardening agent and a coating additive to 400 cc. of a silver halidegelatin emulsion containing 50 g. of gelatin and 20 g. of silverchlorobromide with a silver bromide content of 50 mol percent. Thecoating solution thus 0 tained was applied to a photographic barytapaper of 150 g./m. to thereby prepare a photographic paper. This paperwas developed with the use of a developing liquid having the followingcomposition, and the change in density in relation to the developingperiod at a constant exposure dosage was plotted on the curves shown inFIG. 1.

BRIEF DESCRIPTION OF THE DRAWING In FIG. 1, each curve indicates thefollowing:

Curve A: Hydroquinone, alone was used,

'Curve B: Hydroquinone was used in combination with 1-' Composition ofdeveloping bath: G. Anhydrous sodium sulfite 20 Hydroquinone 3 Anhydroussodium carbonate 15 Potassium bromide 1 Cooperative developing agentshown in the table above (in the molar ratio of 1/20 to hydroquinone).

Water to make the entire solution to 1000 cc.

FIG. 1 illustrates plotted curves showing the relation of density to thedeveloping time of the sample obtained in accordance with an example ofthis invention and a comparative sample.

It will be clearly understood from the curves shown in FIG. 1 that thecompound of this invention has extremely high super additivity to thedeveloping activity.

EXAMPLE A photographic baryta paper of 150 g./m. was coated with acoating solution prepared by adding 30 g. hydroquinone and othernecessary additives to every kg. of a silver halide emulsion containing40 g. of silver chlorobromide (60 mol percent silver bromide) per 125 g.of gelatin, and then dried. The thus prepared photographic paper wasexposed to light through a step wedge, then developed for 4 seconds withthe activated solution used in Example 1, and thereafter stabilized witha stabilizer solution containing ammonium thiocyanate. For purposes ofcomparison, the same treatment was repeated, but adding to the activatedsolution 0.9 g. per liter of the added compound of Synthetic Example 1.The results obtained after measuring specific sensitivity, maximumdensity and gamma are given in Table 2.

It will be understood from this table that the compound of SyntheticExample I greatly accelerates the developing activity of hydroquinone.

EXAMPLE 6 A photographic baryta paper of 150 g./m. was coated with anemulsion containing 2.0 g. of the compound of Synthetic Example 2 perone kg. of the silver halide emulsion of Example 5 and other additives,and then dried to give a photographic paper. This photographic paper andanother sample of photographic paper prepared by using an emulsionwithout containing the added compound of Synthetic Example 2 were eachexposed to light through a step wedge, then developed for 4 seconds withan activated solution containing 20 g. of hydroquinone per liter of thesolution shown in Example 1, and thereafter stabilized with a stabilizersolution containing ammonium rhodanate. The results obtained aftermeasuring the specific sensitivity, maximum density and gamma are givenin Table 3.

TABLE 3 Specific Maximum sensiconcentivity tration Gamma Papercontaining no compound of Synthetic Example 2 1. 00 0.68 0.30 Papercontaining the compound of Synthetic Example 2 14. 80 1. 23 1. 60

It is clearly understood from the above results that OH; R

wherein R is an alkyl group of from 1 to 4 carbon atoms, and n is aninteger of from 2 to 5.

2. The photographic developing process of Claim 1, wherein saidhydroquinone is incorporated in said emulsion layer, in an adjacentlayer to said emulsion layer or in said emulsion layer and an adjacentlayer to said emulsion layer, and said derivative is incorporated insaid alkaline solution.

3. The photographic developing process of Claim 1, wherein saidhydroquinone is incorporated in said alkaline solution, and saidderivative is incorporated in said emulsion layer, in an adjacent layerto said emulsion layer, or in said emulsion layer and an adjacent layerto said emulsion layer.

4. The photographic developing process of Claim 1, wherein saidhydroquinone and said derivative are incorporated in said emulsionlayer, in an adjacent layer to said emulsion layer, or in said emulsionlayer and an adjacent layer to said emulsion layer.

5. The photographic developing process of Claim 1, wherein saidhydroquinone and said derivative are incorporated in said alkalinesolution.

6. The photographic developing process of Claim 2, wherein the amount ofsaid hydroquinone ranges from 5 to 500 grams per mole of said lightsensitive silver halide emulsion.

7. The photographic developing process of claim 3, wherein the amount ofsaid derivative ranges from 0.05 to 50 grams per mole of said lightsensitive silver halide emulsion.

8. The photographic developing process of claim 3, wherein the amount ofsaid hydroquinone ranges from 1 to 70 grams per liter of said alkalinesolution.

9. The photographic developing process of claim 2, wherein the amount ofsaid derivative ranges from 0.01 to 20 grams per liter of said alkalinesolution.

10. The photographic developing process of Claim 1, wherein saidderivative is a member selected from the group consisting of4-(N-ethyl-N-v-hydroxy-propylamino)-2,6-dimethyl phenol hydrochloride,4-(N-n-propyl-N-q-hydroxypropylamino)-2,6-dimethyl phenol sulfate,4-(N-n-butyl N 13 hydroxyethylamino)-2,6-dimethyl phenol hydrochloride,4-(N-ethyl-N-B-hydroxyethylamino)2,6-dimethyl phenol hydrochloride and4-(N- methyl-N-p-hydroxyethylamino) -2,6-dimethyl phenol sulfate.

11. A multi-layer photographic element having at least one lightsensitive silver halide emulsion layer, which contains from 0.05 to 50grams per mole of silver halide of a derivative of p-aminophenol havingthe formula:

HO (C 2)n wherein R is an alkyl group of from 1 to 4 carbon atoms, and nis an integer of from 2 to 5, said p-aminophenol derivative exhibiting asuper-additive developing effect when used for development incombination with hydroquinone.

12. An alkaline solution for photographic development, which containsfrom 0.01 to 20 grams per liter of said solution of a derivative ofp-aminophenol having the formula:

/N OH HO 2);

wherein R is an alkyl group having from 1 to 4 carbon atoms, and n is aninteger of from 2 to 5, said p-aminophenol derivative exhibiting asuper-additive developing effect when used for development incombination with hydroquinone.

13. The photographic developing process of Claim 4, wherein the amountof said hydroquinone ranges from S to 500 grams per mole of said lightsensitive silver halide emulsion.

14. The photographic developing process of Claim 4, wherein the amountof said derivative ranges from 0.05 to 50 grams per mole of said lightsensitive silver halide emulsion.

15. The photographic developing process of Claim 5, wherein the amountof said hydroquinone ranges from 1 to 70 grams per liter of saidalkaline solution.

16. The photographic developing process of Claim 5, wherein the amountof said derivative ranges from 0.01 to 20 grams per lite-r of saidalkaline solution.

17. The photographic developing process according to Claim 1, whereinsaid hydroquinone is incorporated in any one of said emulsion layers, aprotective layer adjacent to said emulsion layer, or an undercoat layeradjacent to said emulsion layer, and said derivative is incorpo rated insaid alkaline solution.

18. The photographic developing process according to Claim 1, whereinsaid hydroquinone is incorporated in said alkaline solution, and saidderivative is incorporated in any one of said emulsion layer, aprotective layer adjacent to said emulsion layer, or an undercoat layeradjacent to said emulsion layer.

19. A photographic developing process according to Claim 1, wherein saidhydroquinone and said derivative are incorporated in any one of saidemulsion layer, a protective layer adjacent to said emulsion layer, oran undercoat layer adjacent to said emulsion layer.

References Cited UNITED STATES PATENTS 3,134,673 5/1964 Ganguin et al.96-55 3,600,176 8/1971 Haist et a1. 96-66 FOREIGN PATENTS 737,795 1/1970Belgium. 1,241,105 7/1971 Great Britain 96-66.3

OTHER REFERENCES Belgium Abstract 737,795 equivalent of British1,241,105.

RONALD H. SMITH, Primary Examiner M. F. KELLEY, Assistant Examiner US.Cl. X.R. 96-67,

